Kotts

I'm sorry, the original question is silly. It presumes that the only explanation for the continued popularity of rim brakes is "resistance". A new technology can be a superior solution in some circumstances, but not in others.

Not everyone needs clipless pedals and those of us who need them don't always need them.

HillRider

Indeed it was and 5 pages later it still is. This topic seems to come up about once a month, generates a lot of heated opinions on both sides and really doesn't (and can't) come to a definitive conclusion. It's become the current Shimano vs. Campy type of topic.

mconlonx

Just try to match up fork length and trail/rake figures to stock as best as possible. Easier now with all the new roadbikes coming out with disk brakes. Extra bonus if you go with through-the-headset brake line routing, like I did on that bike.

mconlonx

I modded the bike with a disk brake to try to sell it as a modded bike at +$$$ on my end, hoping to ride new disk brake fanfare coattails. Didn't sell -- I sold off the front disk brake mod components separate and reverted the bike back to stock.

I had planned to build a new spec bike based on mechanical shifting/hydraulic brakes, but thought better of it, considering my luck with spec bikes in the past, and sold off the frame. I blame my own (lack of) marketing.

As a mechanic, some disk brakes -- mechanical or hydraulic -- are awesome to deal with, others not so much. But the same thing is true of rim brakes, so... The only real absolute is Sturmey Archer drum brakes which rock, and if you are not using them, you are a chump.

davidad

A voice of reason in the wilderness!

Leebo

Unless you do winter commuting through the slush, brown car snot and ice.

AnkleWork

Really? I've never been aware that power is measured in pounds.

HillRider

Power is not, force is. "Power" in this case is generated (or absorbed if you will) by the brakes as they slow or stop the bike. So the upshot of the above posting is that increased force generates more power. An analogy is if you press harder on a car's accelerator (force) the engine generates more power.

AnkleWork

If the OP would just start calling disk brakes "brake reform" then more than half of the suckers will immediately convert. [extra points: then and than in one sentence]

fietsbob

Still wonder where they are projecting their observations/dreams ? Bike Manufacturers selling at Wall Mart? or like Colnago, cost no Object type bikes

Or customers .. those wanting to only pay $99 or those OK with dropping $4000 +?

well biked

I hear ya....but do you use mechanical discs or hydraulics? Extreme cold has the potential to cause problems for some hydraulic systems. I've had it do some weird things to hydraulic brakes in temps not much below freezing. The brakes still work, but the lever feel is quite different than normal. Another example of "there isn't one best brake."

AnkleWork

Was Six referring to the dissipation of kinetic energy when he wrote:

Leebo

My rockhopper has avid BB-7's. They work well for my winter commutes. For me, and my winter conditions it IS the best brake. Rim brakes were less than optimal for my commute through car slush, rutted bike paths and lots of sand and salted roads.

well biked

Mechanical discs have their place, and commuting in very cold temps, particularly in nasty road conditions like you describe, is probably one of the best applications for them.

AnkleWork

I seen 'im!

Six jours

What I am referring to is hand force - and I'm not going to play the "mechanics thread semantics game" because everyone knows what I mean by that. Small increments of hand force at the brake lever create larger increments of braking change with a hydraulic disk than with a caliper brake. That does not result in better modulation. It results in worse modulation. And yes, I know that you can "get used to it" at least to some degree, but that still does not equate to better modulation.

Again, there are many reasons for disk brakes in certain situations. But there are also many reasons against disk brakes in certain situations, and again, the overarching claim that disk brakes are "better" for everyone is obviously untrue.

HillRider

I really apologize for making this thread even longer but, are mechanical discs and calipers prone to ice and slush interference? There have been postings claiming rim brake performance can be interfered with by ice and slush building up on the calipers. Can disc also have this problem, particularly mechanical ones?

AnkleWork

Too late, unfortunately.

Six jours

The last time I got into this sort of argument on this subforum, it was about stem length. I measured a stem with a ruler and posted a pic of it. Then my interlocutor argued that actual measurements were meaningless and that if I had any brains at all I would have used trigonometry instead.

I'm wondering if that guy was you.

cyccommute 

I would answer yes. I did a ride in light frizzle last winter and was unpleasantly surprised when my disc didn't catch. It actually seemed worse than the way rim brakes perform in similar conditions. I attribute it to the reduced rotor size and reduced leverage.

AnkleWork

I guess you could check.

My real point is that both the children and adults here should stay between the lines.

cruiserhead

This doesn't make sense.

Along with your post on page 4, you confuse modulation with poor braking performance.
What you are saying is that because rim braking performance is poor, and requires more force at the lever, it increases modulation.
This is why you feel the old Campy rim brakes have more modulation than new Dura Ace rim brakes (from your post on page 4).

This is a misunderstanding of the physics of what is going on, as well as misunderstanding of what modulation is.

Also, the human equation is not a fixed number ( like 10lbs, in your example). Riders can and do vary the amount of pressure applied to brake levers.

The fact you can apply more braking power with less effort is a good thing, not bad.
That alone, has nothing to do with modulation.
With less effort, there is less fatigue.

Inherent to the design, discs have a far greater range of modulation for the reasons I stated before.
Discs have less inefficient variables, which makes for more predictable and consistent braking.

well biked

I'll defer to those who ride in icy and freezing conditions regularly with mechanical discs.

Raiden

Youre right, my equasion between discs and 29ers is old, though i feel it's relevant. I feel the public didn't really catch the bug for 27.5 like they did 29, except for shorter riders. i don't have a huge amount of exposure to mountain riders anymore, so im not up on the most current mtb trends.

Joe Minton

Hydraulic double-piston disc brakes will become the norm on enthusiast road bikes in the very near future, for the same reasons they are now standard on motorcycles:
1) They are more trouble free.
2) They are more predictable at the lever.
3) They can be more powerful with superior control at the lever.
4) They have greater heat capacity.

Just like with motorcycles, there was resistance to the changes, and, there were developmental problems the first few years. The major developmental difficulties have been pretty much resolved now and resistance will fade.

It takes very little time to get-used to hydraulic disc brakes just as little time is needed to get used to clipless pedals or brifters.

It is my intention to build a touring bike using a Surly LHT disc frame and Shimano XT group set. I may even install a heavy 200mm disc on the front, I'd use cast iron if I could get it. I want to be able to descend the steepest mountain road with the heaviest load and still have plenty of braking power and heat capacity in reserve.

When I raced, fifty years ago, our brakes were dangerously inadequate. There were a number of descents around Southern California that would fade our caliper or center-pull brakes enough that we could not stop or even slow very much.
I once investigated a bicycle accident that, because of fading brakes in a descent, put the rider in a wheel chair. I am sure he was not the only one to be seriously injured by fading brakes.

The latest side-pull caliper brakes, like the new Shimanos, are powerful, fade resistant and provide excellent feel. They are almost as good in these respects as Shimano's latest hydraulic discs.
My carefully setup V-brakes are about as good in power and feel but require frequent attention to keep them that way.

Hydraulic disc brakes will win the day if for no other reason than they do not require the attention of an enthusiast/mechanic like myself to keep them working at peak efficiency.


Joe